Browsing by Author "Birungi, Grace"
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Item Assessment of nonsteroidal anti-inflammatory drugs by ultrasonic-assisted extraction and GC-MS in Mgeni and Msunduzi river sediments, KwaZulu-Natal, South Africa(Environmental Science and Pollution Research, 2017) Gumbi, Bhekumuzi P.; Moodley, Brenda; Birungi, Grace; Ndungu, Patrick G.The occurrence of eight pharmaceuticals was monitored during four seasons (spring, summer, autumn, and winter) along a 250-km stretch of the Msunduzi and Mgeni rivers in KwaZulu-Natal, South Africa. This paper describes an optimized method for the determination of nonsteroidal antiinflammatory drugs (NSAIDs) in sediments. The method combines ultrasonic, centrifuge, and gas chromatographymass spectrometry for the detection of these drugs in solid samples. Most of the parameters that affect the extraction step were optimized. Solid samples were placed in a centrifuge tube and extracted with ethyl acetate:acetone (1:1, two cycles), followed by clean-up with Oasis HLB cartridge and derivatization with N, O-bis(trimethylsilyl) trifluoroacetamide (BSTFA). Satisfactory recoveries were obtained ranging from 66 to 130%, depending on the analyte. Precision expressed as RSD (%) (n = 3) was less than 20%for all analytes. The LODs and LOQs were in the range of 0.024 to 1.90 ng g−1 which allowed to be applied in the analysis solid samples in Msunduzi and Mgeni rivers. In the solid samples analyzed, NSAID concentration ranged from not detected to 221 ng g−1.Item Characterization of urinary metabolites associated with malaria infection using infra‑red spectroscopy and liquid chromatography–mass spectrometry in South Western Uganda(2024-07) Birungi, Grace; Achar, Joan Beryl; Byamugisha, DenisEarly malaria diagnosis improves outcomes during malaria treatment; routine diagnostic techniques rely on blood samples obtained invasively. Therefore, this study used infra-red (IR) spectroscopy coupled with Principle Component Analysis (PCA) to study the urinary profile of malaria patients and that of controls aimed at understanding metabolite perturbation during malaria infection so as to contribute towards development of non-invasive malaria diagnosis methods. Freeze dried human urine samples form malaria infected individuals (cases) and controls were screened in the IR region of 4000 cm−1 to 600 cm−1 and overall spectral differences were observed at wave numbers 1618 cm−1, 1679 cm−1 (amino acids). Peaks at 3030 cm−1 (NH4+) and 940 cm−1 (O–H of carboxylic acids) showed high absorbance in patients compared to controls. Liquid-chromatography–mass spectrometry (LC–MS/MS) was used to quantify amino acids in the urine samples and the results indicated a significant increase of amino acid cystine (P = 0.012). Lysine and tyrosine also increased in patients compared to controls. The use of IR-PCA differentiated clusters of urine samples from patients with malaria from control and the demonstrated amino acid perturbation is consistent with malaria infection. This data provides baseline information for application in development of a non-invasive diagnostic tests for malaria.Article HighlightsInfrared (IR) spectroscopy and Principle Component Analysis (PCA) were used to differentiate urine of malaria patients from controls.LC–MS/MS was used to determine creatinine, tyrosine, cystine, lysine and histidine in urine from malaria patients and controlsThe average concentration of cystine in patients and controls urine differed significantly. Publicly Available Content DatabaseItem Characterization of urinary metabolites associated with malaria infection using infra‑red spectroscopy and liquid chromatography–mass spectrometry in South Western Uganda(Springer Nature B.V, 2024-07) Birungi, Grace; Achar, Joan Beryl; Byamugisha, DenisEarly malaria diagnosis improves outcomes during malaria treatment; routine diagnostic techniques rely on blood samples obtained invasively. Therefore, this study used infra-red (IR) spectroscopy coupled with Principle Component Analysis (PCA) to study the urinary profile of malaria patients and that of controls aimed at understanding metabolite perturbation during malaria infection so as to contribute towards development of non-invasive malaria diagnosis methods. Freeze dried human urine samples form malaria infected individuals (cases) and controls were screened in the IR region of 4000 cm−1 to 600 cm−1 and overall spectral differences were observed at wave numbers 1618 cm−1, 1679 cm−1 (amino acids). Peaks at 3030 cm−1 (NH4+) and 940 cm−1 (O–H of carboxylic acids) showed high absorbance in patients compared to controls. Liquid-chromatography–mass spectrometry (LC–MS/MS) was used to quantify amino acids in the urine samples and the results indicated a significant increase of amino acid cystine (P = 0.012). Lysine and tyrosine also increased in patients compared to controls. The use of IR-PCA differentiated clusters of urine samples from patients with malaria from control and the demonstrated amino acid perturbation is consistent with malaria infection. This data provides baseline information for application in development of a non-invasive diagnostic tests for malaria.Article HighlightsInfrared (IR) spectroscopy and Principle Component Analysis (PCA) were used to differentiate urine of malaria patients from controls.LC–MS/MS was used to determine creatinine, tyrosine, cystine, lysine and histidine in urine from malaria patients and controlsThe average concentration of cystine in patients and controls urine differed significantly. Publicly Available Content DatabaseItem Detection and quantification of acidic drug residues in South African surface water using gas chromatography-mass spectrometry(Chemosphere, 2017) Gumbi, Bhekumuzi P.; Moodley, Brenda; Birungi, Grace; Ndungu, Patrick G.A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60e110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.614 mg L-1. The developed method was applied in the analysis of acidic drugs in Umgeni River system, KwaZulu-Natal South Africa. All of the selected acidic drugs were detected and quantified, their concentration in Umgeni River system ranged from 0.0200 to 68.14 mg L-1.Item Determination of cyanobacterial cyclic peptide hepatotoxins in drinking water using CE(Electrophoresis, 2009) Birungi, Grace; Fong Yau Li, SamFour cyanobacteria hepatotoxins microcystin LR, microcystin RR, microcystin YR, and nodularin were simultaneously determined in drinking water using CZE and MEKC coupled with UV detection. The toxins were satisfactorily separated in both CZE and MEKC modes. Detection limits were in the range of 0.82–4.81 mg/mL, with R2 values of 0.994–0.999. The linearity range tested for the standards was 5–100 mg/mL and RSD percentages were in the range of 1.0–2.5% for retention time and 3.0–10.2% for peak area. When a known amount of standard was spiked into a known volume of water and extracted, recoveries were 90.3% (RR), 101.5% (nodularin), 90.6% (YR), and 88.2% (LR). The use of SPE enabled cleanup and pre-concentration of a real sample to achieve a 100- fold concentration factor. Detection limits after SPE of the real sample spiked with microcystins were 0.090 mg/L (RR), 0.076 mg/L (YR), and 0.110 mg/L (LR), with RSD percentage values of 9.9–11.7% for peak area and 2.2–3.3% for retention time. The technique developed provides an alternative method for determining microcystins at levels of concentration that will be able to meet WHO drinking water guidelines for microcystins.Item Evaluation of organochlorinated pesticide (OCP) residues in soil, sediment and water from the Msunduzi River in South Africa(Environmental earth sciences, 2019) Adeyinka, Gbadebo Clement; Moodley, Brenda; Birungi, Grace; Ndungu, PatrickOrganochlorinated pesticide (OCP) concentrations were evaluated in sediment, soil and surface water of the Msunduzi River as well as the influent, effluent and biosolids from the Darvill wastewater treatment plant (WWTP) of Pietermaritzburg, South Africa. Samples were extracted with dichloromethane using an ultra-sonication method, and cleaned up using multilayered silica gel and analysed using gas chromatography-mass spectrometry. The results showed that all 13 selected OCPs were detected in all the environmental media as well as in the wastewater treatment plant samples. The results revealed that the OCP concentrations along the sites varied based on the anthropogenic activities of the area. The influent of the Darvill WWTP and Du Toit (DUT) site were found to be the most polluted sites. The results from the winter sampling showed highest concentrations of OCPs compared to the spring season. Sediment was found to contain significant amounts of all the selected OCPs with water samples containing the lowest concentrations for both winter and spring seasons. Among the OCPs evaluated, dichlorodiphenyltrichloroethane (DDT) and its metabolites were predominant in all.Item Evaluation of persistent organochlorine pesticides and polychlorinated biphenyls in Umgeni River bank soil, KwaZulu- Natal, South Africa(Water SA, 2019) Gakuba, Emmanuel; Moodley, Brenda; Ndungu, Patrick; Birungi, Graceis study investigated the presence and distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in soil collected along the banks of the Umgeni River, one of the largest rivers in the province of KwaZulu-Natal, South Africa. e analysis was performed using gas chromatography-mass spectrometry (GC-MS). e results showed that the levels of OCPs ranged from 3.58±0.09 ng/g for hexachlorobenzene (HCB) to 82.65±2.82 ng/g for HCH, with an individual mean concentration of 24.33±2.00 ng/g dry weight (dw). e levels of PCBs ranged from 10.46 ng/g for PCB105 to 89.46 ng/g for PCB180, with an average PCB value of 25.47±1.26 ng/g, dw. e highest levels of OCPs and PCBs were found at Northern Wastewater Treatment Plant (mean OCP: 32.39±3.97 ng/g and PCB: 67.87±1.67 ng/g). e two most abundant contaminants in the river were endrin and PCB180.Item Fluoride contamination and its optimum upper limit in groundwater from Sukulu Hills, Tororo District, Uganda(Scientific African, 2020) Egor, Moses; Birungi, GraceThis study was carried out to assess fluoride (F −) concentration and to determine its up- per permissible limit in groundwater from Sukulu Hills, a phosphate mining area in Tororo District, Uganda, where groundwater is the main source of drinking water. Water sam- ples were collected from boreholes and protected springs within a three-kilometer radius from the foot of the Hills. The physico-chemical parameters and F −concentration were analysed using potentiometric methods. The water samples collected had a pH range of 6.0–7.2, electrical conductivity of 148–750 μS/cm, and TDS values of 75–378 mg/L; and these parameters were within the WHO normal range for drinking water. F −concentration in groundwater from boreholes ranged from 0.4 to 3 mg/L, whereas in springs it was from 0.2–2.4 mg/L. High F −levels corresponded with higher TDS values at near-neutral pH. The WHO and Uganda National Bureau of Standards (UNBS) guideline value of 1.5 mg/L F −was exceeded by groundwater from spring S3 and boreholes B3 and B7 (14% of samples) in the study. Given the five-year average weather conditions of Tororo, a modified Galagan equation was applied to calculate the recommended F −level in drinking water for the area, and was found to be 0.4 mg/L. All water sources studied contained average F −levels higher than 0.4 mg/L. These findings imply a possible risk to the local population which depends on this water being exposed to dangers of high F −intake.Item Indoor air quality in rural Southwestern Uganda: particulate matter, heavy metals and carbon monoxide in kitchens using charcoal fuel in Mbarara Municipality(SN Applied Sciences, 2020) Nakora, Nicholas; Byamugisha, Denis; Birungi, GraceThe use of biomass energy over open fires in sub-Saharan Africa is rampant yet it is associated with air pollution. Information on the contribution of common biomass like charcoal to indoor air pollution in Uganda is scarce; therefore, kitchen-indoor air in charcoal fueled kitchens was characterized for fine particulate matter ( PM2.5), heavy metals and carbon monoxide content in Mbarara Municipality Western Uganda. PM2.5 was measured using University of California Berkeley Particle and Temperature Sensor (UCB-PATS), heavy metals were determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and carbon monoxide was measured using a portable, battery-operated, datalogging Drager Pac 7000. In the kitchens assessed, the mean 24-h concentration for PM2.5 was 0.449 mg/m3 in the wet season and 0.526 mg/m3 in the dry season; CO was 41.52 ppm, and all concentrations were higher than the World Health Organization 24-h Air Quality Guideline for PM2.5 of 0.024 mg/m3 and CO of 6.340 ppm. Heavy metals in particulate matter were in concentration ranges of 1.012–9.820 μg/m3 Fe, 0.012–0.092 μg/m3 Cr, 0.060–10.750 μg/m3 Zn, 0.048–0.300 μg/ m3 Cu, 0.004–0.052 μg/m3 Pb and ND—0.004 μg/m3 Cd. All mean metal concentrations were lower than recommended exposure levels by EPA although chronic exposure is a risk to health. Kitchen ventilation and size were found to significantly influence indoor pollutant levels; charcoal fuel significantly contributed to indoor air pollution and is therefore a risk factor to human health.Item Investigation of the effect of exposure to non cytotoxic amounts of microcystins(Metabolomics, 2011) Birungi, Grace; Fong Yau Li, SamThis paper describes a metabolomic approach for investigation of the potential effect of exposure of humans to low amounts of microcystins using HepG2 cell line. Microcystins are hepatotoxins produced by cyanobacteria (blue-green algae) which occur in water bodies with high eutrophication especially those with a slow flow rate or those that are stagnant in warm climates. Mammalian exposure to these compounds has been associated with deleterious effects and in high dosage cases, deaths of animals has been reported. The metabolic profile of HepG2 cells is closely related to that of hepatocytes and therefore serves as a good model due to their human origin. Proton nuclear magnetic resonance spectroscopy (1H NMR) and direct injection mass spectrometry (DIMS) were used to analyse media extracts from the cells and data obtained was reduced by chemometric methods. The use of principal component analysis (PCA) enabled achievement of a visual distinction between the metabolic profiles of samples exposed to microcystins, control samples (unexposed), and those which were exposed to acetaminophen (positive control). A profile of media components showed that some components in the samples exposed to microcystins increased compared to those in control samples. They included amino acids, organic acids, lipids, some purines and pyrimidines. In general exposure to low concentration of microcystin was found to interfere with amino acid metabolism, carbohydrate metabolism, lipid metabolism and nucleic acids metabolism. Furthermore, low concentration of microcystins did not result in significant cell death; rather the cells continued to proliferate.Item Medicinal plant species used by local communities around Queen Elizabeth National Park, Maramagambo Central Forest Reserve and Ihimbo Central Forest Reserve, South western Uganda(Journal of ethnopharmacology, 2019) Gumisiriza, Hannington; Birungi, Grace; Apio Olet, Eunice; Sesaazi, Crispin DuncanThe application of ethnobotanical indigenous knowledge is very important in improving primary healthcare systems among the local communities living around and within protected areas in South Western Uganda. In this area, there are biodiversity endowed Queen Elizabeth National Park (QENP), Maramagambo Central Forest Reserve (MCFR) and Ihimbo Central Forest Reserve (ICFR). Despite the rich floral diversity and cultural heritage, there is no published documentation on the use of medicinal plants in this area. This information can be used as a basis for the selection of medicinal plants for further phytochemical and pharmacological studies. Study aim: This study identified and documented the use of medicinal plants, plant parts used, and mode of preparation and administration by the local communities living around and within QENP, MCFR and ICFR. Materials and methods: A cross-sectional study was used to collect data from 202 informants using semi-structured questionnaires, open interviews and field visits. Ethnobotanical data was analyzed using use reports (UR), frequency of citation (FC) and Informant Consensus Factor (FIC). The plants species were identified by botanists and voucher specimens were deposited. Results: A total of 302 medicinal plant species were mentioned by informants, out of which only 211 species belonging to 65 families and 165 genera were collected, identified and documented. The remaining 91 species were not available for collection and informants stated that they had become very rare within the study area. Herbs (35.8%) were the main source of herbal medicine. Leaves (60.4%) were the most commonly used plant parts used in the preparation of herbal remedies. Most of the medicinal plants were harvested from the wild, either growing in abundance (41%) or as rare species (21%). The most common mode of administration was oral, while other exceptional modes such as touching with bare hands and sweeping over the affected part were reported for the first time. The medicinal plant species were reported to treat 134 physical ailments, which were grouped into 16 ICPC-2 disease categories. Digestive disorders (854 UR) and general and unspecified disorders (507) scored the highest FIC value of 0.83. The highest number of medicinal plants (146 plant species) was used for treatment of digestive disorders. Among the species with higher use reports, Gouania longispicata had the highest frequency of citation (FC=174) and was mentioned to be used to treat 41 physical ailments. The most important ailment treated by Gouania longispicata was allergy with 102 use reports. Conclusions: A variety of medicinal plants are used by communities living near protected areas in South Western Uganda. Most species were used in the treatment of digestive disorders, followed by general and unspecified disorders. Much as allergy has not been identified as a major threat by the health sector in Uganda, the study found out that it is one of the prevalent ailments in the study area. While the therapeutic value of some of the documented medicinal plant species, especially those with higher frequency of citation have been scientifically validated, the efficacy and safety of other species with wide application need to be investigated. In this study, we recommend further scientific studies on Gouania longispicata to validate its wide usage in the study area.Item Medicinal Plants Used to Treat ‘African’ Diseases by the Local Communities of Bwambara Sub-county in Rukungiri District, Western Uganda(Journal of Ethnopharmacology, 2020) Gumisiriza, Hannington; Sesaazi, Crispin Duncan; Apio Olet, Eunice; Kembabazi, Owen; Birungi, GraceEthnopharmacological relevance: In Africa, traditional medicine encompasses a diverse range of practices, including herbalism and spiritualism, where some diseases are believed to be “African” since they can only be traditionally treated. Indigenous knowledge on the management of “African” diseases using medicinal plants is still handed down orally from generation to generation by tribal societies of tropical Africa, and with the rapid westernization of these societies there is a pressing need to record local knowledge before it is lost forever. Aim: This study documented medicinal plant species associated with the management of “African” diseases by the local communities of Bwambara sub-county in Rukungiri district, Western Uganda. Methods: A cross-sectional study was conducted using semi-structured questionnaires and interviews. The data collected included names of plant species, plant parts used, diseases treated, methods of preparation, and mode of administration of the herbal remedies. A total of 196 informants participated in the study. Data were analyzed and presented using descriptive statistics and the Informant consensus factor. Results: We documented 67 medicinal plant species distributed over 27 families and 62 genera. The most commonly reported species belong to Asteraceae family. The most frequently used medicinal species were Chenopodium opulifolium (27), Sesbania sesban (26), Thevetia peruviana (25), Leonotis nepetifolia (23), Momordica foetida (23), Euphorbia hirta (21) and Cassia mimosoides (20). Leaves were the most commonly used plants parts and decoctions were the main method of preparation. Water was the main medium used for the preparation of the remedies which were administered orally while petroleum jelly was the main medium for those which were used as ointments. The medicinal plant species reported are used to treat 39 conditions which were clustered into 10 International Classification of Primary Care (ICPC) disease categories. There is a high degree of consensus among the informants on which medicinal plant species they use for different diseases especially disorders in the following categories: neurological (FIC = 0.90), general and unspecified (FIC = 0.87), digestive (FIC = 0.86) and female genital (FIC = 0.82). Conclusion: Local communities of Bwambara sub-county in Rukungiri district, Western Uganda use a rich diversity of medicinal plant species in the management of various “African” diseases. Therefore, collaboration between users of medicinal plants and scientists is paramount, to help in the discovery of new drugs based on indigenous knowledge.Item Metabolomics Approach for Investigation of Effects of Dengue Virus Infection Using the EA.hy926 Cell Line(Journal of proteome research, 2010) Birungi, Grace; Meijie Chen, Sheryl; Pheng Loy, Boon; Ng, Mah Lee; Yau Li, Sam FongThis paper describes a multiplatform analytical approach combining proton nuclear magnetic resonance (1H NMR) spectroscopy and mass spectrometry (MS), together with pattern recognition tools in a metabolomic study used to investigate the effects of dengue virus infection. The four serotypes of dengue, DEN-1, DEN-2, DEN-3, and DEN-4, were inoculated into the EA.hy926 cell line, which was then incubated for various time intervals. Principal component analysis (PCA) of the 1H NMR and MS data revealed metabolic profile patterns or fingerprint patterns that can be attributed to specific virus serotypes. Distinct effects of infection by each serotype were demonstrated, and these differences were attributed to changes in levels of metabolites (including amino acids, dicarboxylic acids, fatty acids, and organic acids related to the tricarboxylic acid (TCA) cycle). The study demonstrated application of metabolomics to improve understanding of the effect of dengue infection on endothelial cells’ metabolome.Item Occurrence and significance of polychlorinated biphenyls in water, sediment pore water and surface sediments of Umgeni River, KwaZulu-Natal, South Africa(Environmental monitoring and assessment, 2015) Gakuba, Emmanuel; Moodley, Brenda; Ndungu, Patrick; Birungi, GraceThe Umgeni River is one of the main sources of water in KwaZulu-Natal, South Africa; however; there is currently a lack of information on the presence and distribution of polychlorinated biphenyls (PCBs) in its sediment, sediment pore water and surface water. This study aims to determine the occurrence and significance of selected PCBs in the surface water, sediment pore water and surface sediment samples from the Umgeni River. Liquid-liquid and soxhlet extractions were used for water or pore water, and sediments, respectively. Extracts were cleaned up using a florisil column and analysed by gas chromatography-mass spectrometry. The total concentrations of eight polychlorinated biphenyls were 6.91–21.69 ng/mL, 40.67–252.30 ng/mL and 102.60–427.80 ng/g (dry weight), in unfiltered surface water, unfiltered sediment pore water and surface sediments, respectively. The percentage contributions of various matrices were 4, 36 and 60% for unfiltered surface water, unfiltered pore water and sediment, respectively. The highest concentrations of PCBs were found in water, pore water and sediment collected from sampling sites close to the Northern Wastewater Treatment Works. The highest chlorinated biphenyl, PCB 180, was the most abundant at almost all sampling sites. To our knowledge, this is the first report on occurrence of polychlorinated biphenyls in the Umgeni River water, pore water and sediment system and our results provide valuable information regarding the partitioning of the PCBs between the water and sediment systems as well as the organic chemical quality of the water.Item Occurrence of selected pharmaceuticals in water and sediment of Umgeni River, KwaZulu-Natal, South Africa(Environmental Science and Pollution Research, 2015) Matongo, Solomon; Birungi, Grace; Moodley, Brenda; Ndungu, PatrickSelected pharmaceuticals including antibiotics, antipyretics, a stimulant, an antiepileptic and an antipsychotic drug were determined in wastewater, surface water and sediment along the Umgeni River which is the main source of water to Durban City in KwaZulu-Natal, South Africa. Samples were analysed using high-performance liquid chromatography coupled to a mass spectrometer (HPLC-MS/MS) after clean up and pre-concentration by solid phase extraction (SPE). At the wastewater treatment plant outlet, the antipyretic ibuprofen was detected in concentrations up to 12.94 μg/L and 15.96 ng/g in wastewater and bio-solids, respectively. The antipsychotic clozapine was detected in concentrations up to 14.43 μg/L and 18.75 ng/g in wastewater and bio-solids, respectively. Other pharmaceuticals namely sulfamethazine, sulfamethoxazole, erythromycin, metronidazole, trimethoprim, acetaminophen, caffeine and carbamazepine were also detected but in lower concentration compared to clozapine and ibuprofen (<10 μg/L or 10 ng/g). Clozapine and ibuprofen were detected at high concentrations in the surface water and sediment of Umgeni River. The highest concentration of clozapine (78.33 μg/L) was detected at the business park, while that for ibuprofen (62.0 μg/L) was detected at the point where a tributary, Msunduzi, joins Umgeni. Metronidazole was only detected in sediment, and caffeine (2243.52 ng/g) was detected at the highest concentration in the sediment at the blue lagoon sampling site. The antibiotic sulfamethoxazole was also detected in appreciable amounts up to 507.34 ng/g in the sediment at the Msunduzi tributary sampling site. The data collected implies that while insufficiently treated wastewater contributes to surface water contamination, human activities also contribute appreciably to the pharmaceutical loading of River Umgeni.Item Pesticide residues in vegetables produced in rural south-western uganda(Food Chemistry, 2021) Ngabirano, Hannington; Birungi, GraceThis study investigated seven pesticides in vegetables produced in rural South-western Uganda to determine their suitability for human consumption. Pesticide residue concentrations (ppm) were determined using QuEChERS method, LC–MS/MS, GC-MS/MS and UV-Vis. Cypermethrin, dimethoate, metalaxyl, profenofos, malathion, dichlorvos and mancozeb concentrations detected in sprayed samples ranged between 0.00403 to 0.05350, 0.17478 to 62.60874, 0.12890 to 3.55681, 0.00107 to 0.59722, 0.03144 to 0.63328, 0.00240 to 0.34102 and 0.00001 to 0.00244, respectively. The residues exceeded MRLs in sprayed samples (59.52 %), unsprayed samples (18 %) and market samples (8 %). The quality index of the market vegetables was found to be optimal (14.29 %), good (75 %), adequate (3.57 %) and inadequate (14.29 %). Pesticide residues may lower food quality and pose risk to human health. Therefore, regulation and monitoring pesticide residues in vegetables produced in south-western Uganda in order to avoid harmful effects on human health would be paramount.Item Pesticide Use In Vegetable Production In Rural Uganda - A Case Study of Kabale District, South Western Uganda(Research Square, 2020) Ngabirano, Hannington; Birungi, GraceA study to investigate commonly grown vegetables, commonly used pesticides, and pesticide use practices was conducted in Kabale District, in south-western Uganda. This is because indiscriminate pesticide use and poor application practices can leave pesticide residues in food rendering it unsafe for consumption. The study revealed extensive pesticide application in Brassica oleracea; var. capitata (cabbage), Brassica oleracea; var. botrytis (cauliflower), Solanum lycopersicum, (tomato) and Beta vulgaris (beet root). Information obtained using interviews revealed that 16.5% traders sell pesticides and 70% farmers spray pesticides on vegetables. Only 18% of farmers could interpret instructions correctly on a given pesticide container label. All farmers (100%) had never attended any pesticide use training. Cypermethrin, dimethoate, dichlorvos, metalaxyl, profenofos, malathion and mancozeb were common pesticides used in spraying vegetables however 42% of the farmers mixed different pesticides for use. Limited knowledge about pesticide application, inability to interpret instructions, non-observation of waiting period before harvesting, mixing pesticides and lack of training on pesticide use for farmers are potential risks to food safety. There is need to address knowledge gaps on safer pesticide application in order to attain safe agricultural productivity for sustainable food security, human health and community development in Kabale District, Uganda.Item Pharmaceutical residues in water and sediment of Msunduzi River, KwaZulu-Natal, South Africa(Chemosphere, 2015) Matongo, Solomon; Birungi, Grace; Moodley, Brenda; Ndungu, PatrickThe little data about pharmaceutical residue contamination in African water bodies motivated our study on the occurrence of pharmaceutical residues in the water and sediment of Msunduzi River in the KwaZulu-Natal province of South Africa; and in the Darvill wastewater treatment plant found in Msunduzi catchment. Samples collected along the River and wastewater treatment plant were extracted and analysed for pharmaceutical residues selected based on statistics of drug usage in South Africa i.e. antipyretics, antibiotics, caffeine, an antiepileptic and an antipsychotic drug were determined using HPLC–MS/MS. In all the matrices investigated, the antipyretic ibuprofen had the highest concentration of up to 117 lg L 1, 84.60 lg L 1 and 659 ng g 1 in wastewater, surface water and sediment respectively. Antibiotics were detected in generally low concentrations of <10 lg L 1 in surface water samples and up to 34.50 lg L 1 in wastewater; moreover they were not completely removed during wastewater treatment. The percentage removal efficiency of the studied group was 6.55–98.00% for antipyretics, 73.33– 98.90% for antibiotics, 48.80% for the anti-epileptic drug and 86.40% for Caffeine. Clozapine exhibited a negative removal. In surface water, Henley dam exhibited a high concentration of the pharmaceutical residues and the highest concentration of metronidazole in sediment (up to 1253.50 ng g 1) detected. Metronidazole was only detected in sediment and bio-solids.Item Quantitative analyses of selected polychlorinated biphenyl (PCB) congeners in water, soil, and sediment during winter and spring seasons from Msunduzi River, South Africa(Environmental monitoring and assessment, 2018) Adeyinka, Gbadebo Clement; Moodley, Brenda; Birungi, Grace; Ndungu, PatrickThe lack of information and the need for knowledge on the organic pollutants within the area of KwaZulu-Natal together with the global problem of water supply have prompted our investigation into the analyses of eight polychlorinated biphenyl (PCB) congeners in the Msunduzi River of KwaZulu-Natal, South Africa. Soil, sediment, and water sampleswere collected at ten different sites along the river during winter and spring seasons. Soil and sediment samples were extracted using ultra sonication with dichloromethane while water samples were liquid-liquid extracted using dichloromethane. All sample extracts were cleaned-up using a multi-layer silica gel column and analyzed with gas chromatography-mass spectrometry. Quality assurance measures were also determined. The percentage recoveries for water were 53–128 for all the PCBs analyzed, while sediment recoveries ranged between 69 and 105%. The highest total concentrations of the PCBs in sediment were 214.21–610.45 ng/g dw at the Du Toit sampling site and 30.86–444.43 ng/g dw basis at the wastewater treatment inlet for winter and spring, respectively. Soil PCB concentrationswere 76.53–397.75 ng/g dw at the Msunduzi Town sampling site and 20.84– 443.49 ng/g (dry weight) at the Du Toit sampling site for winter and spring, respectively. In addition, high PCB concentrations were found in effluent of the wastewater treatment inlet compared to other sampling sites, which ranged between 0.68–22.37 and 2.53–35.69 ng/ mL for winter and spring seasons, respectively. In all the sampling sites selected for this study, Du Toit afforded the highest PCB concentration levels and the lowest was after chlorination at the Darvill wastewater treatment plant. The results presented are new and it is the first study of organic pollutants such as PCBs that has been carried out on this river.Item Spectrophotometric Determination of Low Levels of the Orthophosphate Anion as Molybdenum Blue using Sodium Thiosulphate Reducing agent(Oriental Journal of Chemistry, 2020) Nalumansi, Irene; Birungi, Grace; Moodley, Brenda; Tebandeke, EmmanuelA simple spectrophotometric method for the determination of low levels of the orthophosphate (PO4 3-) in environmental water systems is reported. The method is based the formation of the phosphomolybdate from the condensation of molybdate and orthophosphate in aqueous acid medium followed by reduction with sodium thiosulphate to form phosphomolybdenum blue. The system obeys Beer’s law at 880 nm (λmax) in the 0.005–0.06 mg P mL-1 phosphate concentration range. Molar absorptivity, Sandell’s sensitivity and correlation coefficient values for the determination were 57526 L mol-1 cm-1, 0.2835 μg cm-2 and 0.9948 respectively. The limit of detection was 2.213 x 10-3 mg P mL-1. The results of PO4 3- determination in water samples obtained using the spectrophotometric method developed in this study, compare favourably with those generated using the Murphy and Riley method which is commonly used for this analysis. Therefore, the study ably demonstrates the suitability of the present spectrophotometric method for analysis of the orthophosphate in environmental water samples.